First off, this Perian project is saving my butt - I'm a windows guy who has started teaching at a school where faculty are all issued macbooks. Perian has given support for all my documentaries in divx, xvid, x.264, mkv, etc - fantastic! The problem is that I have a number of lectures in powerpoint where I have embedded video clips from various documentaries that play and work within the presentation itself. Very handy for lecturing, etc. With Perian installed, I am getting video on all my clips and their various formats no problem, EXCEPT my mkvs (which i believe were encoded with x.264 and acc audio). My MKV clips will play video, which is great (before it was just a blank window), HOWEVER, the sound works for about 1-2 seconds and stops. If I track/jump to another point in the clip, the sound plays again for 1-2 seconds, and then stops. I don't want to have to find all of the documentaries, convert them to mp4 or something else, and then edit them and reinsert them if I can help it. It's a lot of work.

Just to clarify could you answer:Do the videos play fine in powerpoint on Windows?Do the videos play fine in QT Player and not through powerpoint (assuming you have access to the mkvs themselves)?The audio always plays, but only for 1-2 seconds, correct?Do you have other mkv components installed that could be interfering and do you have Perian 1.2.3?

I remember something like this, but I could have sworn it was before 1.2.3.Also, as a test, you can try other versions, such as 1.2.2 (you'll have to restart powerpoint after you install it).

Thanks for the response. To answer your questions:1. Yes, they play fine in power point in Windows2. With the Perian files installed, they play fine in quick time outside of power point.3. Audio always plays, but only 1-2 seconds before stopping. Foward to another spot, it plays agains and then audio stops again - same amount of time, 1-2 seconds.4. Perian 1.2.3 is the version installed. I do have an x.264 component listed in the quicktime library as well as the perian. It doesn't affect it outside of powerpoint however, and I'm not sure if this is Mac's own codec, or an external one (from Perian perhaps?)

If it doesn't work, i'll try an earlier version and see if that does it.

Sounds like Powerpoint's interaction with QuickTime isn't as it should be. We tend to use QuickTime player as the standard for playback, and anything that doesn't work when it does tends to be doing something wrong. MKV is a different animal in terms of how it works, and it could be that Powerpoint is assuming that all QuickTime media is fully indexed (which is most common) and doesn't properly handle a background importer.

Is it possible for you to extract the MKV files out of the Powerpoint document? If so, you could consider opening the MKV in QuickTime Player 7 (assuming you have pro, if not I think I have an AppleScript around somewhere that works around it), tell it to save as a self-contained movie, and see if that works in Powerpoint. This should give an additional data point as to what the issue is.